Control of flow of granular



June 16, 1953 c, s, REED 2,642,206

CONTROL OF FLOW OF GRANULAR MATERIAL I Filed D80. 4, 1947 2 Sheets-Sheet 1 June16,1953 s) REED 2,642,206

CONTROL OF FLOW OF GRANULAR MATERIAL Filed Dec. 4, 1947 2 Sheets-Sheet 2 INVENTOR.

mu, V

Patented June 16, 1953 CONTROL OF FLOW OF GRANULAR MATERIAL Carl S. Reed, New York, N. Y., assignor to The Lummus Company, New York, N. Y., a corporation of Delaware Application December 4', 1947, Serial No. 789,586

This invention relates to improvements inthe control of flow of a granular contact material by gravity through a chamber in a system wherein contact is effected between such material and a medium in a fluid state.

In certain continuous systems employed for conducting a hydrocarbon conversion process or an adsorption process, for examples, a granular catalyst or adsorbent, in a packed mass, is passed by gravity through a chamber and therein brought into contact withgaseous media to be converted or adsorbed. The chamber is often quite large, ranging in diameter from to 20 feet and sometimes as high as 150 feet, and the contact material may be passed through the chamber at the rate of 100 tons, or more, per hour. most desirable that the rate of descent of the material be substantially equalized throughout the entire horizontal cross section of the chamber. In other words, the descent of the material should be substantially level, in order that all of the material throughout the cross section be changed at approximately the same time and fresh contact surface be presented to the gaseousmedia. Heretofore, the obtaining of such descent of the material has. presented a dimcult prob lem. Owing to frictional contact of the material with the walls of the chamber descent of the material adjacent the walls lags behind the descent of material at the center of the chamber. Then, in the usual outlet arrangements, the ma.- terial. at the center flows out of the chamber to the exclusion of material in the outer portion ofv the cross section so that the latter material forms a. fixed, or slowlymoving, wall. A concentration of fines of the material within a portionof the chamber will also retard descent of thematerial through that portion.

An important object of the present invention is to provide an improved method and improved apparatus for regulating discharge of granular material by gravity from a chamber and, by such regulation, controlling fi'ow of the material in a manner to ensure substantially level descent thereof within the chamber.

Other objects and advantages of the inventhe line 22 of Fig. 1 and shows [a valve device forming apart of the flow control apparatus;

Fig. 3 is a horizontal section on the'line 3-3 of Fig. 1;

For eilicient contact performance it is- 12 Claims; (Cl. 222-429) Fig. 4 is a horizontal section on the line 44 of Fig. 1, upon a reduced scale; and

Fig. 5 is a vertical section on the line 5-5 of Fig. 1, upon a reduced scale.

According to the invention, the granular ma terial is discharged by gravity from the contact chamber through ports which are evenly distributed 'over the area of the bottom of the chamber. The material so discharged is collected upon a support located at a level suitably spaced beneath the bottom of the chamber, and the collected material is caused to form a cone of re pose beneath each of the discharge ports. Each cone when completely formed halts further ,dis-

charge from the respective port, and all of the collected material is retained upon the support until all cones are complete. Thereby, equal volumes of the material are discharged from equal sections of the horizontal cross section of the chamber and a substantially level descent of the material within the chamber is obtained. After all of the cones have completely formed, the said ports are closed by means independent of the cones and then the material of the cones is released to fall from the support. Then, the support is prepared for collection again and the chamber discharge ports are all reopened to discharge the material upon the support and again form cones of repose thereon. This cycle is repeated at intervals suited to complete all cones within each cycle and to obtain a desired rate of total flow of the material through the. chamber.

Referring to the drawings, I indicates a casing defining a vertical chamber 2 which may, for example, be a catalytic reaction or conversion chamber for a continuous hydrocarbon conversion system of' a type wherein a packed mass of granular catalyst is passed downwardly through the chamber forcontact with fluid reactants, then elevated to the top of a regeneration chamber, passed downwardly therethrough and regenerated and then again elevated to the top of the conversion chamber 2 for reuse therein.

The casing is vertically elongated and of uniform cross sectional form and size throughout most of its height. It is shown as square in cross 7 section, but it maybe of other suitable form.

The lower end portion 3 of the casing is downwardly tapered [and has connected thereto an inclined discharge pipe 4. Within the casing a deck 5 is mounted at a level suitably spaced above the lower end of the casing. This deck forms the bottom of the contact chamber and is provided with down-spouts 6 equally spaced over the are-a of the deck and all. of the same internal diameter,

and the same length and forming discharge ports for the chamber. These ports are so positioned as to centrally underlie equal portions of the cross sectional area of the chamber. Another deck 7 3 is also mounted within the casing at a level suitably spaced below the deck 5. Both of said decks extend over the entire cross sectional area of the casing, and the lower deck I has down spouts 8 equal in number to the spouts 6 and in respective vertical alignment therewith. These spouts form discharge ports, all of the same diameter, for the lower deck. Said lower deck bears upstanding partition walls Ia dividing the area of the deck into equal squares each centeredwith respect to an upper spout 6 and a lower spout 8. These walls define bins to collect material discharged through the respective spouts 6.

A short distance below the level of the lower ends of the spouts 6 there is a closure element 9. In the present instance, this element is in the form of a flat skeleton plate formed with a set of shutter sections l corresponding in number to the spouts 6 and similarly spaced. At opposite edges thereof the plate 9 is suspended by links I I each pivotally connected at its upper end at fixed points within the casing, as at 2, and pivotally connected at its lower end to the plate. These links support the plate for horizontal parallel movement to shift the shutter sections E0 of the plate into and out of register with the spouts for opening and closing the latter. A closure plate 9c similar to plate 9 and having similar shutter sections Illa is disposed in the same relation to the spouts 8 and similarly suspended by links I la to shift for opening and closing the spouts.

Fluid pressure operated mechanism is shown for shifting the closure plates or valves 9 and 9a. Mechanism of a different character may, however, be employed. In the present instance the mechanism includes a pair of duplicate cylinders l3 and I311 mounted at the outer side of one of the walls of the casing and disposed horizontally and substantially at the levels of the plates 9 and 9a. respectively. Cylinder 1 3 has a piston 14 with a rod fitted to work within a tubular projection 18 on said casing walland operatively connected, as at IT, with the closure plate l0. Similarly, cylinder 13a has a piston [4a with a rod [5a fitted to work within a tubular projection lSa on said casing wall and operatively connected to the closure plate 9:1, as at Ha. Operation of the pistons I4 and Ma is controlled by a valve device I8. I

The valve device may be of any suitable design to efiect operation of the pistons in the required order. It is shown as including a flat base plate 19 having a chest 20 mounted thereon and a valve 2| mounted to slide upon said plate. The plate has a row of ports including, from left to right in Fig. 2, a port opening into a pipe 22 which leads to the right-hand end of cylinder 13, wtih reference to Fig. l, a port opening into a pipe 23 which leads to the left-hand end of cylinder 13a, and exhaust port 24, a port opening into a pipe 25 which leads to the left-hand end of cylinder l3, and a port opening into a pipe 25 which leads to the right-hand end of cylinder i311. Air, steam or other suitable gaseous fiuid is supplied to the valve chest through the pipe 21. The valve 2! has a stem 28 working through a stuffing box on the chest. A suitable motordriven timing device 29 has a rotor 30 rotated at a required fixed rate and operatively connected to the valve stem 'by a pitman' 3|. Any suitable timing means may be employed. Such means, per se, forms no part of the present invention and detail illustration of same is therefore omitted.

The tapered lower portion 3 of the casing I forms a hopper to receive the granular material has moved farther toward the right does it es-' discharged from the lower deck 7. Discharge from this hopper is controlled automatically in response to variations in the level of the material within the hopper. Any suitable level control mechanism may be employed for that purpose. One of known type is shown. It includes an electrical condenser device 32 within the upper portion of the hopper and responsive to the presence or the absence of material between its plates. Said device is electrically connected to a control device 33 of known type which, through a pipe 34, is connected to a diaphragm motor 35 of a well-known type mounted upon the outside of the hopper. Controller 33 admits air or other suitable gaseous fluid to motor 35 and exhausts it therefrom. The diaphragm of the motor has a stem 36 operatively connected to a lever 31 fulcrumed upon the mounting of the motor and operatively connected to a gate valve 38 in the discharge pipe 4. The level control mechanism per se forms no part of the present invention and therefore detail illustration of the devices comprising it is omitted.

The apparatus is operated as follows to perform the improved method of flow control: As shown in Fig. 2, the valve 2| is in a position to admit fluid pressure from the valve chest through the pipes 25 and 26 to the left-hand end of cylinder I3 and to the right-hand end of the cylinder [3a. The valve also connects the pipes 22 and 23 to the exhaust port 2 3. Thereby, the piston Ma is held in a position to retain the lower closure plate 9a in a closed position, with the shutter sections of the plate in register with the spouts 8 of the lower deck I, as shown in Fig. 1. At the same time, the piston I4 is held in a position to retain the upper closure plate 9 in open position, with the shutter sections Ill out of register with the spouts 6. The granular material, indicated at M, can then flow through the spouts tothe lower deck 1 until cones of repose form under the spouts and obstruct further discharge from the chamber 2. Suflicient time is allowed for all of the cones to build up to equality in volume, and thus insure discharge of equal volumes of the material through all of the spouts, for level descent of the material within the chamber. The valve device l8 and the timing means 29 are devised to provide the desired time. The rotor 30 is rotated at the desired rate and imparts a harmonic motion to the valve 2| which aifords a desired dwell at the end of the valve stroke. In addition, the valve and ports are so correlated as to require material movement of the valve before connections are established thereby to shift the pistons 14 and Ma and move the closure plates.

Continued rotation of the rotor 30 causes shifting of the valve toward the right, with reference to Fig. 2. The first result of such shift, with reference to the pistons l4 and Ma, is that a fluid pressure connection is established through the pipe 22 to admit pressure to the right of piston l4, and a connection is established through the pipe 25 and the exhaust port 24 to exhaust pressure at the left of piston l4. Thereby, said piston is moved to the left and the closure plate 9 is shifted so that the shutter sections thereof cut across the peaks of the cones and are brought into register with the spouts 6 to close them independently of the cones. Only after the valve 2| tablish a connection through the pipe 23 to admit pressure to the left of piston Ma and establish a connection through the pipe 26 and the exhaust port 24 to exhaust pressure from the right of pisacaaaoe ton; [4m Thepiston [4a then shifted. to: the right. to move the closure plate 9a to" open position, with the shutter sections out of register with the spouts 8-. Thereby, the material of the cones is. released tofallfrom the deck I, through the spouts and into the hopper.

On the reverse stroke of. the valve. 2|, a. fluid. pressure connectionis first. establishedthrough the. pipe 25 to the right of. piston [4d, and an exhaust. connection; to the. leftaof said. piston is es tablishedthrough the pipe 235 and the exhaust port. Thereby, the piston enabled to shift the lower closure plate 9a to closed" position whilethe upper closure plate 9' remains in closed position, so. that-premature. discharge. through the nozzles fi ls prevented. As the valve 21. moves farther toward the-:left it. establishes. a fluid pressure connection through the. pipe.- 25 to the. Ieft=of piston l4 and an exhaust connection through'the pipe 22 and the exhaust-port 25'. The piston. 14 is. then moved to the right to shift the closure plate 9 to open position, for discharge through the spouts B to the lower deck 1. Thus the cycle of movement of the closure platesis completed. The cycle is repeated by continuous rotation. of the. rotor 38 and at a raterequired to obtain a desired rate of total. flow of. the material through thechamberZ.

A substantially uniform rate of discharge of the material from the hopper 3 is provided for by thelevel control mechanism previously described herein. In response to fluctuations in the level of. the material within the hopper the diaphragm motor 35 will be operated to adjust the valve so as to obtain continuous discharge at a substantially uniformrate. Suchcontrol is important to prevent overloading of the hopperand to obtain continuous delivery of the material at a uniform rate to an elevator conveyor when such a conveyor is employed in the system.

The invention is particularly devised for em-- ployment in. a continuous catalytic reaction system. for the conversion of petroleum hydrocarbons. In. that connection it may be used in systems for catalytic cracking, dehydrogenation, de-.

sulferization, etc. It may also beused advantageously in continuous adsorption and'clesorption systems, continuous coking systems and in other fields where granular material is itself treated for drying or-other purposes.

In a catalytic system for the conversion of: pe-

troleum hydrocarbons and suited for. employment.

of. the present invention, the catalyst particles comprising the granular material may range in size from 4 to 60. mesh. and the materialmay, for

examples, be natural or treated clays, bauxites, alumina and certain synthetic associations of silica and alumina or silica and alumina to which small percentages of other materials may be added such as certain metallic oxides. In some cases also the'particles, instead of themselves being of catalytic material, may be impregnated with catalytic material so that they serve as catalyst carriers'; The particles may'also be of some regular shape such as spherical or pellet form. The term granular is intended to comprehend such forms as well as a natural granular form.

It is of course to be understood that the present disclosure of my invention is merely illustrative and in nowise limiting, and that the invention comprehends'such modifications as will come within the-scope of the claims.

I claim:

1 Ina contact process wherein a m-ass'of solid contact" material in a divided state descends by gravity through a chamber; the steps. for-causing substantially level descent. of the material of. said mass within the chamber comprising discharging' substantially equal quantities. of the. material of said mass: by gravity ,from the bottom of the chamber through ports of substantially equal depth at least several times the width of the port at the bottom of: the chamber spaced: and distriband having a maximum area in horizontal section several times the area of the port, to ob. struct further discharge through the port, re-- taining the discharged -material upon said collecting' level until a complete cone of repose has formed. beneath each ofsaid ports, releasing the collected material for fall of substantially all of the material forming the cones from. the collecting level after all of said cones have been formed and thereby providing space for new cones, obstructing discharge through said ports during said fall of the material, and repeating. said steps in the order recited.

' 2.111 a contactprocess wherein a mass of solid contact material in a divided state descends by gravity" through a chamber, the: steps for causing substantially leveldescent of the materialv within the: chamber comprising discharging substantially equal quantities of the. material of said mass from the bottom of. the chamber through ports of substantially equal area centered.respec-- tively with reference to equal areas totaling the area of the horizontal cross section ofv the chamber, collecting the discharged material within a region beneath said discharge ports and forming of the discharged material equal cones of'repose each beneath a. respective one of said ports and of a depth at least several times the width of the port and having a maximum area in horizontal section at least several times the area. of the port to obstruct further discharge through the port, retaining the discharged materialwithin said region until a complete cone of repose has formed beneath each of said ports, removing substantially all of the. material forming said cones from said region after all of. the cones have been formed and thereby providing space for new cones, obstructing discharge through said ports during said removal of the material, and repeating: said; steps: in the: order recited.

3;. In a. contact process wherein amass of solid. contact material in av divided state descends by gravity through a chamber; the. steps for obtaining substantially level descent ofv said material. through. the. chamber, comprising discharging by gravity the. material. of said mass. through ports said ports the material discharged therethrough and forming of the material so collected a mound of repose of a depth at least several times. the Width. of the port and having a maximum areain horizontal section at least several times the area of the port and stopping. further discharge through the portby the forming of said mound,

retaining the discharged material beneath theports untila complete-mound of repose: has

for new mounds, preventing discharge through the ports during said fall of the material, and repeating said steps in the order named.

4. In the passage of a mass of solid material in a divided state through a chamber by gravity, the steps for obtaining substantially level descent of said material through the chamber, comprising discharging by gravity the material of said mass through ports at the bottom of the chamber spaced and distributed over the vertical projection of the area of the horizontal cross section of the chamber and in quantities at said ports to obtain substantially equal withdrawal of the material through equal portions of said area, collecting beneath each of said ports the material discharged therethrough and forming of the material so collected a mound of repose of a depth at least several times the width of the port and having a maximum area in horizontal section at least several times the area of the port and stopping further discharge through the port by the forming of said mound, retaining the discharged material beneath the ports until a complete mound of repose has formed beneath each port, removing substantially all of the material of said mounds from beneath the ports to provide space for new mounds, preventing discharge through the ports during said removal of the material, and

repeating said steps in the order recited.

5. In the passage of a solid material in a divided state downwardly along a course by gravity, the steps for controlling such passage, comprising discharging the material through an exit at the lower end of the course, collecting the discharged material within a region below said exit and forming of the collected material a mound of repose of a depth at least several times the width of said exit, and having a maximum area in horizontal section at least several times the area of the exit and downwardly diverging opposite sides with clear space at their upper portions at least, to halt further discharge through the exit, passing a closure for said exit to closed position beneath the exit by transversely shearing entirely through the peak portion of the mound of repose between said opposite sides, removing substantially all of the material of the mound from said region while said closure is in closed position to provide space for a new mound, and repeating said steps in the order recited.

6. The combination of a chamber through which granular material is passed downwardly by gravity; and apparatus for controlling discharge of the material from said chamber and obtaining substantially level descent of the material therein, comprising a bottom structure for the chamber in a substantially horizontal plane, the chamber being of substantially uniform shape and area in' horizontal cross section for a substantial distance upwardly from said bottom structure and the latter having spaced discharge ports sized and distributed over the area of the vertical projection of said cross section for substantially equally distributed discharge of the material throughout said area, closure means for said parts mounted for shifting between open and closed positions, a deck mounted in a position spaced beneath said ports and having beneath each port collecting surface for the material discharged through the port, said surface being spaced downwardly from the port a distance at least several times the width of the port and having an area at least several times the area of the port, thereby enabling the discharged material to form mounds of repose beneath the ports, the deck also having ports equal in number to said chamber ports and substantially in vertical alignment therewith, respectively, for discharge of the material of said mounds, closure means for said deck ports mounted for shifting between open and closed positions, and timed power-operated mechanism operable upon said two closure means to cause shifting of same periodically in cycles each including closure of said chamber discharge ports, opening of said deck ports, closure of the deck ports and opening of the chamber ports, in the order named, and to keep the chamber ports open for a substantial portion of the time period of each cycle, for completion of the mounds of repose beneath all of said chamber ports.

7. The combination as claimed in claim 6 wherein the closure means for the chamber ports includes shutter portions mounted to shift substantially horizontally beneath said ports and shear through the peak portion of the mounds of repose in their closing movement.

8. The combination as claimed in claim 6 wherein the deck has upstanding walls forming an enclosure around each deck port to segregate the material discharged through the respective chamber ports.

9. The combination as claimed in claim 6 wherein said chamber discharge ports are of equal size and are evenly distributed over said projected area.

10. The combination as claimed in claim 6 wherein the said chamber discharge ports are defined by spouts extending downwardly from the body of said bottom structure of the chamber.

11. The combination as claimed in claim 6 wherein the said closure means for the chamber ports includes shutter portions mounted to shift substantially horizontally beneath said ports and shear through the peak portion of the mounds of repose in their closing movement and said ports are shaped to give the mounds a substantially conical shape.

12. The combination as claimed in claim 6, wherein the said closure means for the chamber ports includes shutter portions mounted to shift substantially horizontally beneath said ports and shear through the peak portions of the mounds of repose in their closing movement and wherein said ports are shaped to give the mounds a substantially conical shape and said shutter portions are exposed for shedding of material therefrom onto said deck.

CARL s. REED.

9 References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 706,940 Herring Aug. 12, 1902 807,484 Moss Dec. 19, 1905 998,994 Smith July 25, 1911 1,139,269 Goodman et al. May 11, 1915 1,663,574 Venable Mar. 27, 1928 1,685,512 Varusky Sept. 29, 1928 1,799,113 Miedbrodt Mar. 31, 1931 2,079,802 Hank May 11,1937 2,368,672 McNamara Feb. 6, 1945 2,381,505 Lindh'olm Aug. 7, 1945 2,408,221 Michel Sept. 24, 1946 2,415,328 Anderson et a1. Feb. 4, 1947 2,486,200 OConnor Oct. 25 1949 

